1. Field of the Invention
The present invention relates to an elevator machine. More particularly, it relates to an elevator machine consisting of a drive motor, a drive shaft purposed to be driven by the motor, a gear assembly purposed to reduce the rotational speed of the motor, a brake, and a traction sheave purposed to transmit motion of the drive shaft to the elevator car by means of ropes, the drive shaft being supported at its ends by bearings, one of which is constituted by the toothing between the drive shaft and one or more gearwheels belonging to the gear assembly.
2. Description of Related Art
The commonest type of reduction gear used between the drive motor and traction sheave of an elevator is the worm gear. However, as the worm gear has a relatively low efficiency, there has been a trend towards the use of other types of reduction gear. Worm gears have been replaced e.g. by spur gears, which have a better efficiency, especially at start-up. A disadvantage with currently used spur gears is that the gear assemblies are bulky and therefore impractical.